CN115735126A - Battery module with improved assembly structure of voltage sensing part and battery pack including same - Google Patents

Abstract

A battery module according to the present invention includes: a cell stack composed of a plurality of battery cells stacked in one direction; and a sensing module arranged on the cell at the front or rear of the stack for voltage sensing and electrical connection of the battery cells, wherein the sensing module includes: a main frame formed to cover the cell stack The front or rear part of the battery cell has a plurality of lead wire extraction holes through which the electrode leads of the battery cells can be extracted; a plurality of bus bars, the plurality of bus bars are arranged on the on the main frame to be spaced apart from each other along one direction; and a printed circuit board of rigid material, the printed circuit board is attached to the main frame and has a plurality of sensing tips, the plurality of sensing tips The tips are arranged to be attachable to and detachable from corresponding bus bars.

Description

Battery module with improved assembly structure of voltage sensing components and battery module including the battery battery pack for cell module

technical field

The present disclosure relates to a battery module, and more particularly, to a battery module having an improved assembly structure of voltage sensing parts such as bus bars, bus bars required for voltage sensing of battery cells, Sensing components and connectors.

This application claims priority from Korean Patent Application No. 10-2020-0149664 filed in Korea on Nov. 10, 2020, the disclosure of which is incorporated herein by reference.

Background technique

A semi-permanent battery capable of converting electrical energy into chemical energy and repeatedly performing charging and discharging is called a secondary battery to be able to be distinguished from a primary battery that cannot be reused after being used once.

Examples of the secondary battery include a lithium secondary battery, a nickel-cadmium (Ni-Cd) battery, a lead-acid battery, a nickel-metal hydride (Ni-MH) battery, a zinc-air battery, and an alkaline manganese battery. Among them, lead-acid batteries and lithium secondary batteries may be the most commercialized secondary batteries.

In particular, lithium secondary batteries have recently been actively used as batteries for electric vehicles due to advantages of high energy density, light weight, small size, excellent safety, low discharge rate, and long life. For reference, lithium secondary batteries are generally classified into cylindrical, square, and pouch-type batteries according to their manufacturing shape, and are used as batteries for energy storage systems (ESS) and other electrical devices in addition to batteries for electric vehicles .

Currently, it may not be possible to obtain sufficient output from only one lithium secondary battery (cell) to drive an electric vehicle. In order to apply a secondary battery as an energy source for an electric vehicle, a battery module in which a plurality of lithium ion battery cells are connected in series and/or in parallel should be constructed, and a battery pack is generally constructed which includes battery modules for series connection and Functionally maintain the battery module's battery management system (BMS), cooling system, battery disconnect unit (BDU), wiring harness, etc.

When the battery module includes a pouch-type secondary battery cell as shown in FIG. 1 , the electrode leads 1a, 1b of the pouch-type secondary battery cell are Soldered to the bus bars 3 located on the front or the front and the rear of the battery module.

For voltage sensing of secondary battery cells, a flexible printed circuit board (FPCB) 5 is connected to each bus bar 3 . The voltage information of the secondary battery cells is transmitted to the BMS (not shown) through the connector 7 mounted on the FPCB 5, and the BMS monitors the state of each secondary battery cell and based on the voltage information of the secondary battery cells to control charging and discharging.

In the battery module according to the related art, each bus bar 3 is laser welded to a corresponding sensing terminal 5 a of each FPCB to connect the FPCB 5 to the bus bar 3 . In this case, many welding defects occur, and welding quality management is not easy. During the above assembly process, FPCBs, which are generally more expensive than printed circuit boards (PCBs), are often discarded due to soldering defects. Also, connector pins of the connector are soldered on the FPCB. In this case, the mounting process of the connector is also not easy, and it is considered that the connector including the connector pins soldered on the FPCB is susceptible to shock or vibration.

Contents of the invention

technical problem

The present disclosure is designed to solve the problems of the related art, and thus the present disclosure aims to provide a battery module in which a bus bar, a sensing member, and a connector for voltage sensing are compared with the related art The assembly structure is easier and more stable.

It will be easily understood by those skilled in the art that other objects of the present disclosure can be achieved by means and combinations thereof shown in the following description and claims.

Technical solutions

According to an embodiment of the present disclosure, a battery module includes: a cell stack including a plurality of battery cells stacked in one direction; and a sensing module located at the cell on the front or rear of the stack for voltage sensing and electrical connection of the plurality of battery cells, wherein the sensing module includes: a main frame formed to cover the cell The front surface or the rear surface of the body stack, and includes a plurality of lead holes through which the electrode leads of the plurality of battery cells are drawn out; a plurality of bus bars, the plurality of bus bars are located in the on the main frame to be spaced apart from each other in one direction; and a printed circuit board formed of a rigid material, the printed circuit board including a plurality of sensing tips detachably ground on the corresponding bus bars, and the printed circuit board is attached to the main frame.

The main frame may include: a bus bar installation part recessed to correspond to each of the plurality of bus bars; and a board installation part provided on the plurality of bus bars. above the bus bar mounting portion, and recessed to correspond to the printed circuit board.

Each sensing tip of the plurality of sensing tips may include: a base portion soldered to the printed circuit board; and a connection portion extending a length from the base portion, and Attached to or detached from the bus bar by rotating forward or backward.

The connecting portion may include a bent end portion, wherein the bus bar includes a slit into which the end portion of the connecting portion is press-fitted.

The end portion of the connecting portion may include one or more protrusions formed in a convex pattern.

The bus bar may be provided in a frame shape to surround the outside of the lead hole.

The sensing module may further include a direct connector directly connected to an edge of the printed circuit board.

The direct connector may include a connector housing including an upper board portion contacting a surface of the printed circuit board and a lower board portion contacting the printed circuit board. the other surface of the board and engages with the edge of the printed circuit board; and a connector terminal, the connector terminal is provided in the connector housing, and contacts are provided on the surface of the printed circuit board on the wire.

A void space may be provided between a portion of the edge of the printed circuit board and the front surface of the main frame to connect the connector housing.

According to another aspect of the present disclosure, a battery pack includes the battery module.

beneficial effect

According to an aspect of the present disclosure, there may be provided a battery module in which an assembly structure of a bus bar, a sensing member, and a connector for voltage sensing is easier and more stable than related art.

According to the present disclosure, since a rigid printed circuit board is used as the sensing member, and the sensing tip of the rigid printed circuit board can be detachably press-fitted into the bus bar, the sensing tip and the bus bar can be easily assembled And reprocessing can be performed when necessary.

Moreover, according to the present disclosure, since the assembly structure is formed such that the connector is not mounted but mechanically engaged with the printed circuit board, the connector can be more easily and securely assembled on a rigid printed circuit board.

The effects of the present disclosure will be more clearly understood through the following examples of the present disclosure. It will also be easily understood that the effects of the present disclosure can be achieved by the means shown in the claims of the present disclosure and combinations thereof.

Description of drawings

FIG. 1 is a partial perspective view illustrating a part of a front surface of a battery module according to the related art.

FIG. 2 is a perspective view illustrating a configuration of a battery module according to an embodiment of the present disclosure.

FIG. 3 is a perspective view illustrating a sensing module according to an embodiment of the present disclosure.

FIG. 4 is an exploded perspective view illustrating the sensing module of FIG. 3 .

FIG. 5 is a view illustrating a state before a sensing tip and a bus bar are connected according to an embodiment of the present disclosure.

6 is a cross-sectional view illustrating a state after a sensing tip and a bus bar are connected according to an embodiment of the present disclosure.

FIG. 7 is a partially enlarged view of FIG. 6 .

FIG. 8 is an enlarged view illustrating an assembly structure between a rigid printed circuit board and a connector according to an embodiment of the present disclosure.

Detailed ways

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms used in the specification and appended claims should not be construed as being limited to the ordinary and dictionary meanings, but to allow the inventors to define the terms as appropriate for best interpretation. On the basis of principles, interpretations are made based on meanings and concepts corresponding to the technical aspects of the present disclosure. Therefore, the descriptions presented herein are only preferred examples for the purpose of illustration only, and are not intended to limit the scope of the present disclosure, so that it should be understood that other equivalents and modifications can be made thereto without departing from the scope of the present disclosure. .

These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Accordingly, the thickness and size of each element shown in the drawings may be exaggerated, omitted, or schematically drawn for clarity. Accordingly, the size of each element does not entirely reflect an actual size or ratio.

FIG. 2 is a perspective view illustrating a configuration of a battery module according to an embodiment of the present disclosure. FIG. 3 is a perspective view illustrating a sensing module according to an embodiment of the present disclosure. FIG. 4 is an exploded perspective view illustrating the sensing module of FIG. 3 .

Referring to FIGS. 2 to 4 , a battery module according to an embodiment of the present disclosure includes a cell stack 100 , a sensing module 200 , a front cover 300 and a rear cover 400 .

The cell stack 100 may be a group of battery cells 110 . For example, the cell stack 100 may be formed by erecting the battery cells 110 in the up-down direction and stacking the battery cells in the left-right direction. The battery cell 110 refers to a pouch-type battery cell 110 . The battery cell 110 of the present embodiment is a bidirectional lead type pouch type battery cell in which a positive electrode lead and a negative electrode lead are positioned opposite to each other.

The pouch type battery cell 110 includes an electrode assembly, an electrolytic solution, and a pouch case for encapsulating the electrode assembly and the electrolytic solution. The electrode assembly has a structure in which a positive electrode plate, a separator, and a negative electrode plate are repeatedly stacked, and each of the positive electrode plate and the negative electrode plate includes an electrode tab. Inside the pouch case, one or more electrode tabs are connected to the electrode lead 111 , and the electrode lead 111 extends to the outside of the pouch case to function as an electrode terminal of the battery cell 110 .

The bag case for sealing and containing the electrode assembly and the electrolytic solution may include a metal film, such as an aluminum film, to supplement electrochemical performance and improve heat dissipation of the electrode assembly and the electrolytic solution. An aluminum thin film may be located between the inner adhesive layer and an insulating layer formed of an insulating material to ensure electrical insulation.

The sensing module 200 is installed on the front and rear of the cell stack 10 where the electrode lead 111 of each battery cell 110 is located.

The sensing module 200 for electrical connection and voltage and temperature sensing of the battery cells 110 includes a main frame 210 , a plurality of bus bars 220 , a printed circuit board 230 and a direct connector 240 .

The main frame 210 as a plate-shaped structure may have an area corresponding to the front (or rear) of the cell stack 100 and may be disposed to cover the front (or rear) surface of the cell stack 100 . The main frame 210 may be formed of an insulating material such as plastic through injection molding.

The front (or rear) of the cell stack 100 may be covered by the main frame 210, and the electrode leads 111 of each battery cell 110 may be extracted through a plurality of lead holes 213 formed in the main frame 210, and may are soldered to corresponding bus bars 220 .

The main frame 210 according to the present embodiment includes a bus bar mounting portion 211 , a board mounting portion 212 and a connector connection portion O on the front surface. The bus bar mounting portion 211, the board mounting portion 212, and the connector connection portion O are provided for connection and separation between the bus bar 220 and the sensing tip 231 described below, stable mounting of the rigid printed circuit board 230, and direct The connection space of the connector 240 is ensured.

The bus bar mounting part 211 is arranged at a central portion of the main frame 210 in the left-right direction, and is each recessed to correspond to the shape of the bus bar 220 to be mounted. That is, the bus bar installation part 211 has a width and a depth corresponding to the width and thickness of the bus bar 220 . Each bus bar 220 corresponding to the bus bar mounting portion 211 is inserted so that no stepped portion is formed between the surface of the main frame 210 and the surface of the bus bar 220 . In other words, when the bus bar 220 is inserted into the bus bar installation part 211 , the bus bar 220 does not protrude to the outside of the surface of the main frame 210 .

The board mounting part 212 where the printed circuit board 230 is to be assembled may be disposed above or below the bus bar mounting part 211 . In the present embodiment, the board mounting portion 212 is formed right above the bus bar mounting portion 211 . The board mounting part 212 is recessed to correspond to the shape of the printed circuit board 230 . That is, the board mounting part 212 has a width and a depth corresponding to the width and thickness of the printed circuit board 230 . Similar to the bus bar mounting portion 211 , the printed circuit board 230 is inserted into the board mounting portion 212 so that no stepped portion is formed between the surface of the main frame 210 and the surface of the printed circuit board 230 . When the printed circuit board 230 is inserted into the board mounting part 212, the printed circuit board 230 may be fixed by using the bolts B or by using an adhesive or tape instead of the bolts.

In this configuration, the surface of the bus bar 220 and the surface of the printed circuit board 230 are on the same plane. In this case, the bus bar 220 and the sensing tip 231 can be easily connected, which will be described in detail below.

The connector connection portion O is a recessed portion of the edge of the board mounting portion 212 . Since the connector connection part O is provided, a certain space may be secured between the edge of the printed circuit board 230 and the main frame 210 , and the direct connector 240 may be connected through the space to be engaged with the edge of the printed circuit board 230 .

Since the mechanical rigidity of the electrode lead 111 of the battery cell 110 is insufficient, the bus bar 220 is used for stable electrical connection of the battery cell 110 . The bus bar 220 may be formed of copper, aluminum or clad metal thereof.

The plurality of bus bars 220 may be fixed by being conformably inserted into the bus bar installation part 211 of the main frame 210 . Although not shown, the bus bar 220 may additionally be fixed using an adhesive, a hook, or a bolt.

In this embodiment, six bus bars 220 are arranged on the front main frame 210 of the cell stack 100 at equal intervals, and five bus bars (not shown) are arranged at equal intervals on the cell stack 100 on the rear main frame 210. The bus bar 220 may be formed in any of various shapes, such as a straight bar shape, a U shape, or a quadrangular frame shape.

Among them, since the bus bar 220 having a quadrangular frame shape can be installed on the main frame 210 to surround the outside of the lead hole 213, the electrode leads 111 can be drawn out from the lead hole 213, and then some of the electrode leads 111 can be pulled out. Welded to the left of the quadrangular frame and the rest of the electrode leads can be welded to the right of the quadrangular frame, so a large number of electrode leads 111 can be easily welded.

Accordingly, in the present embodiment, the bus bar 220 having a quadrangular frame shape is used. Two of the bus bars 220 serve as positive and negative electrode terminals of the battery module. For this purpose, the shapes of the positive electrode terminal T1 and the negative electrode terminal T2 are added to the first bus bar 220 and the sixth bus bar 220 which are the outermost bus bars on the front main frame 210 .

In this configuration, the positive electrode leads of the battery cells 110 of the first group are welded to the first bus bar 220 of the front main frame 210, and the negative electrode leads of the battery cells 110 of the first group are connected with the The positive electrode leads of the battery cells 110 are welded together to the first bus bar 220 of the rear main frame 210 . Next, the negative electrode leads of the battery cells 110 of the second group and the positive electrode leads of the battery cells 110 of the third group are welded to the second bus bar 220 of the front main frame 210 . In this manner, the negative electrode lead of the battery cell 110 of the last group is welded to the sixth bus bar 220 of the front main frame 210 . (The N-th group of battery cells 110 refers to one or more battery cells 110 bundled.) In this case, all the battery cells 110 constituting the cell stack 100 may be connected in series through a plurality of bus bars 220 and/or connected in parallel.

As described above, the battery cells 110 are connected in series through the bus bar 220 in units of groups or bundles. In this case, the voltage of each of the battery cells 110 connected in series may be determined by measuring the voltage at each of the bus bars 220 .

The printed circuit board 230 may be used as a sensing member for sensing a voltage at each bus bar 220 . Since the printed circuit board 230 can transmit a large amount of signal or power while occupying a small space in the battery module, the printed circuit board 230 can be effectively used as a voltage sensing member.

In the related art, a flexible printed circuit board (FPCB) capable of three-dimensional (3D) wiring has been widely used as a sensing member. However, the FPCB has a problem in that the FPCB is susceptible to impact and expensive, and as described in the background art, laser welding should be performed when the FPCB is connected to the bus bar 220 . Accordingly, the present disclosure uses a printed circuit board 230 formed of a rigid material, which may be firmly attached to the main frame 210 , instead of an FPCB.

As shown in FIGS. 3 and 4 , a printed circuit board 230 formed of a rigid material according to an embodiment of the present disclosure may include a plurality of sensing tips 231 detachably disposed on a bus bar 220 and each configured The wire 232 that transmits the signal of each sensing tip 231 is formed, and can be fixedly attached to the board mounting part 212 . In this case, since the printed circuit board 230 is formed of a rigid material, the printed circuit board 230 can be firmly fixed to the board mounting part 212 by using the bolts B. Referring to FIG.

Each sensing tip in the plurality of sensing tips 231 may include: a base portion 231a, which is soldered to the printed circuit board 230; and a connection portion 231b, which extends from the base portion 231a with a certain length and passes Rotate forward or backward to be attached to or detached from the bus bar 220 .

Also, as shown in FIG. 5, the connection part 231b includes an end part 231c bent at an angle of about 90°. The bus bar 220 includes a slit 221 formed by cutting with a certain depth in the thickness direction. The slit 221 is formed at a position where the end portion 231c of the connection portion 231b can be inserted when the sensing tip 231 is rotated.

In these configurations, as shown in FIG. 6 , by rotating the connecting portion 231b of the sensing tip 231 in a state where the bus bar 220 and the printed circuit board 230 are attached to the main frame 210, the end portion 231c of the connecting portion 231b may be press fit into the slot 221 of the bus bar 220 .

As described above, the bus bar 220 and the printed circuit board 230 are located on the bus bar mounting part 211 and the board mounting part 212 , respectively, so that the surface of the bus bar 220 and the surface of the printed circuit board 230 are on the same plane. Accordingly, when the end portion 231c of the connection portion 231b is inserted into the slit 221 of the bus bar 220 by rotating the connection portion 231b of the sensing tip 231, the remaining portion of the connection portion 231b can be parallel to the surface of the connection portion 231b. way is tightly attached.

Also, the sensing tip 231 may include at least one convex portion 231d formed in a convex pattern on the end portion 231c of the connection portion 231b. Referring to FIG. 7 , the sensing tip 231 according to the present embodiment includes a convex portion 231d in an uneven or convex pattern on the end portion 231c of the connecting portion 231b. When the end portion 231c of the connection portion 231b is inserted into the slit 221 of the bus bar 220, a part of the convex portion 231d collides with the inner wall surface of the slit 221 and is compressed. In this case, the restoring force of the convex portion 231d is applied, so that the contact between the inner wall surface of the slit 221 and the convex portion 231d is strongly maintained.

Also, in order to allow one end of the end 231c of the connection part 231b to be caught outside the slit 221, one end of the end 231c of the connection part 231b may have a ring shape 231e so that the connection part 231b is not easily separated from the slit 221.

In this configuration, when the sensing tip 231 and the bus bar 220 are connected, the connection can be easily and quickly performed, and when necessary, the separation can be performed, so it is different from the connection between the sensing tip 231 and the bus bar 220. Compared with laser welding, it is also possible to replace only one of the bus bar 220 and the printed circuit board 230 .

The direct connector 240 may be used to transmit voltage information of the battery cell 110 sensed by the sensing tip 231 of the printed circuit board 230 to a battery management system (BMS) (not shown).

As shown in FIG. 8 , a direct connector 240 according to an embodiment of the present disclosure may be configured to be directly connected to an edge of a printed circuit board 230 .

In detail, the direct connector 240 may include: a connector housing inserted into the printed circuit board 230 and engaged with the printed circuit board 230; a plurality of connector terminals provided at the connection and a plurality of cables 244 connected to a plurality of connector terminals in a one-to-one manner and extended to the outside.

The connector housing includes: an upper plate portion 241a and a lower plate portion 241b that form a space for accommodating connector terminals; and a latch portion 242 and a plate holding lead 243 that The portion 242 and the board holding lead 243 form a locking means for the printed circuit board 230 .

The upper plate part 241a and the lower plate part 241b may form the body of the connector housing. The upper plate part 241a and the lower plate part 241b are formed such that the front parts are spaced apart from each other by the thickness of the printed circuit board 230 to be deeply inserted into the edge of the printed circuit board 230 and the rear parts are connected to each other to be integrated.

When the connector housing is connected to the edge of the printed circuit board 230, the front side of the upper plate portion 241a contacts the front surface of the printed circuit board 230, and the front side of the lower plate portion 241b contacts the rear surface of the printed circuit board 230, and the latch A lock 242 and a board holding lead 243 are additionally coupled to the printed circuit board 230 to prevent movement of the direct connector 240 . Insertion holes, into which connector terminals may be individually inserted, may be formed in rear portions of the upper and lower plate parts 241a and 241b.

Also, in the present embodiment, an empty space is provided between a part of the edge of the printed circuit board 230 and the front surface of the main frame 210 . This empty space corresponds to the connector connection part O of the main frame 210 . Since the lower board part 241b of the connector housing may be located in the empty space, the direct connector 240 may be connected to the edge of the printed circuit board 230 without being obstructed by the upper end of the main frame 210 .

As described above, in the battery module according to the present disclosure, since the sensing tip 231 of the printed circuit board 230 can be detachably press-fitted into the bus bar 220, the sensing tip 231 and the bus bar 220 can be easily assembled, And reprocessing can be performed when necessary. Also, because the assembly structure is formed such that the direct connector 240 is mechanically engaged with the printed circuit board 230, the connector can be installed more securely and easily than in the prior art.

A battery pack according to the present disclosure may include one or more battery modules according to the present disclosure. Also, in addition to the battery modules, the battery pack according to the present disclosure may further include a battery pack case for accommodating the battery modules and various devices for controlling charging and discharging of each battery module, such as a main BMS, a current sensor, and fuse.

The battery module according to the present disclosure may be applied to vehicles such as electric vehicles or hybrid vehicles. That is, the vehicle may include the battery module according to the present disclosure.

Although one or more embodiments of the present disclosure have been described with reference to the examples and drawings, the present disclosure is not limited thereto, and those of ordinary skill in the art will understand that, without departing from the present disclosure as defined by the appended claims, range of circumstances in which various changes in form and detail may be made.

Those of ordinary skill in the art will understand that when terms indicating directions such as up, down, left, right, front and back are used, these terms are for explanatory convenience only and may vary depending on the position of the target object, the position of the observer Wait and change.

Claims (10)

1. A battery module, comprising: a cell stack including a plurality of battery cells stacked in one direction; and a sensing module located on the front or rear of the cell stack for voltage sensing and electrical connection of the plurality of battery cells, Wherein, the sensing module includes: a main frame formed to cover a front surface or a rear surface of the cell stack, and including a plurality of lead holes through which electrode leads of the plurality of battery cells are drawn; a plurality of bus bars positioned on the main frame to be spaced apart from each other in one direction; and a printed circuit board formed of a rigid material, the printed circuit board including a plurality of sensing tips detachably disposed on corresponding bus bars, and the printed circuit board is attached to the main frame. 2. The battery module according to claim 1, wherein the main frame comprises: a bus bar mounting portion recessed to correspond to each of the plurality of bus bars; and A board mounting portion provided above the bus bar mounting portion and recessed to correspond to the printed circuit board. 3. The battery module of claim 1, wherein each sensing tip of the plurality of sensing tips comprises: a base that is soldered to the printed circuit board; and A connecting portion extending at a length from the base and being attached to or detached from the bus bar by being rotated forward or backward. 4. The battery module according to claim 3, wherein the connection part comprises a bent end part, Wherein, the bus bar includes a slit, and the end portion of the connecting portion is press-fitted into the slit. 5 . The battery module according to claim 4 , wherein the end portion of the connection portion includes one or more protrusions formed in a convex pattern. 6. The battery module according to claim 1, wherein the bus bar is provided in a frame shape to surround the outside of the lead hole. 7. The battery module of claim 1, wherein the sensing module further comprises a direct connector directly connected to an edge of the printed circuit board. 8. The battery module according to claim 7, wherein the direct connector comprises: a connector housing including an upper plate portion and a lower plate portion, the upper plate portion contacts the printed circuit board a surface of the printed circuit board, the lower board portion contacts the other surface of the printed circuit board and engages with the edge of the printed circuit board; and a connector terminal, the connector terminal is provided in the connector housing , and contact the wires that are provided on the surface of the printed circuit board. 9. The battery module of claim 8, wherein a void space is provided between a portion of the edge of the printed circuit board and a front surface of the main frame to connect the connector housing. 10. A battery pack comprising the battery module according to any one of claims 1 to 9.

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